As a guy who has sold more than one car because I couldn't make it work with my back, I am very sympathetic.
My back is also a bit of a mess. I had to modify my Yukon seats when I bought it (and is one of the many reasons I likely will keep it for the rest of my life, driving life anyway). Recently when we bought my wife a new Toyota Highlander, I had to remove the lumbar adjustor in the seat back and cut some custom foam to adjust for my back's support. To get her seats in a tolerable position, my head is maybe 1/4" from the headliner. To be honest, when we brought it home, I was pretty sure I would never be able to make it work for me. But persistence paid off and I now can drive it without it killing me.